Definition of: ferment

(fûr′ment) noun
1. A substance productive of fermentation, as yeast; an enzyme.
2. Fermentation.
3. Excitement or agitation.
—v.t. & v.i. (fər·ment′)
1. To undergo fermentation or produce fermentation in; work.
2. To stir with anger; agitate or be agitated by emotions or passions. [<F <L fermentum <fervere boil]
—fer·ment′a·ble or ·i·ble adjective
—fer·ment′·a·bil′i·ty noun